diff --git a/lib/msun/ld128/s_exp2l.c b/lib/msun/ld128/s_exp2l.c
index a94b89220737..31178e40624d 100644
--- a/lib/msun/ld128/s_exp2l.c
+++ b/lib/msun/ld128/s_exp2l.c
@@ -371,7 +371,7 @@ exp2l(long double x)
 			if (u.xbits.manh != 0
 			    || u.xbits.manl != 0
 			    || (hx & 0x8000) == 0)
-				return (x); 	/* x is NaN or +Inf */
+				return (x + x);	/* x is NaN or +Inf */
 			else 
 				return (0.0);	/* x is -Inf */
 		}
diff --git a/lib/msun/ld80/s_exp2l.c b/lib/msun/ld80/s_exp2l.c
index 8a0dbe2d3309..14dfc1d87f21 100644
--- a/lib/msun/ld80/s_exp2l.c
+++ b/lib/msun/ld80/s_exp2l.c
@@ -226,7 +226,7 @@ exp2l(long double x)
 	if (ix >= BIAS + 14) {		/* |x| >= 16384 or x is NaN */
 		if (ix == BIAS + LDBL_MAX_EXP) {
 			if (u.xbits.man != 1ULL << 63 || (hx & 0x8000) == 0)
-				return (x); 	/* x is NaN or +Inf */
+				return (x + x);	/* x is +Inf or NaN */
 			else
 				return (0.0);	/* x is -Inf */
 		}
diff --git a/lib/msun/src/s_exp2.c b/lib/msun/src/s_exp2.c
index 63b8997cfd97..c46750f42ba0 100644
--- a/lib/msun/src/s_exp2.c
+++ b/lib/msun/src/s_exp2.c
@@ -351,7 +351,7 @@ exp2(double x)
 		if(ix >= 0x7ff00000) {
 			GET_LOW_WORD(lx,x);
 			if(((ix & 0xfffff) | lx) != 0 || (hx & 0x80000000) == 0)
-				return (x); 	/* x is NaN or +Inf */
+				return (x + x);	/* x is NaN or +Inf */
 			else 
 				return (0.0);	/* x is -Inf */
 		}
diff --git a/lib/msun/src/s_exp2f.c b/lib/msun/src/s_exp2f.c
index 1b9299f56e36..43da2f6b66f6 100644
--- a/lib/msun/src/s_exp2f.c
+++ b/lib/msun/src/s_exp2f.c
@@ -104,7 +104,7 @@ exp2f(float x)
 	if(ix >= 0x43000000) {			/* |x| >= 128 */
 		if(ix >= 0x7f800000) {
 			if ((ix & 0x7fffff) != 0 || (hx & 0x80000000) == 0)
-				return (x); 	/* x is NaN or +Inf */
+				return (x + x);	/* x is NaN or +Inf */
 			else 
 				return (0.0);	/* x is -Inf */
 		}